On arrival at St Petersburg's airport Mr Stepashin said: "I brought with me a team of experienced investigators. I think we will clear it up soon."

He added that that finding her killers is a matter of personal honour for him.

Prime Minister Yevgeny Primakov said he was "angered by the news" of Mrs Starovoitova's murder, adding: "This banditry must be done away with immediately."

The Communist leader, Gennady Zyuganov, called for emergency measures to fight crime in Russia.

Mrs Starovoitova, 52, was an outspoken defender of human rights and a former advisor to President Yeltsin on ethnic minorities.

The BBC Moscow Correspondent, Robert Parsons, says contract killings of prominent figures have become commonplace in Russia but Mrs Starovoitova was widely respected, and there will be popular outrage at the killing.

Police have not speculated on the cause of her murder but amongst possible motives investigators will have to ask whether anti-Semitism and ethnic intolerance - important issues for Mrs Starovoitova - could be linked to her killing